This application is in response to RFA-CA-06-003, Applications of emerging technologies for Cancer Research. This RFA:" invites applications for research projects to evaluate the usefulness of emerging molecular technologies that are ready for initial application to clinical or biological questions in cancer research. Projects should be designed to demonstrate that the technology is robust and yields reproducible measurements. Projects should also be designed to gather preliminary data to support the use of the technology in a future project(s) with a clinical or biological focus." The application combines the efforts of researchers in the Departments of Chemistry and Pathology at the University of Washington and at the Fred Hutchinson Cancer Research Center. These researchers will perform a pilot study to evaluate new technology for cancer research, chemical cytometry. This technology monitors protein and biogenic amine expression in single cells, and will be evaluated for the study of cells isolated from biopsies obtained from patients in the Seattle Barrett's Esophagus Cohort. We will systematically determine the variance in cellular composition within Barrett's esophagus biopsies We will dissect 20 cells from a single crypt isolated from a biopsy and perform chemical cytometry on those cells. This study will provide understanding of the variance in protein expression along a crypt and during development of a stem cell into its differentiated form. We will perform chemical cytometry on cells isolated from three crypts obtained from a single biopsy. These crypts will be closely related and the study will provide information on the intraclonal variation. We will perform chemical cytometry on cells isolated from crypts obtained from three biopsies from the same patient. This study will provide information on the interclonal variation. We will generate fingerprints from 5 patients, which will provide information on the between-patient variance. As a result of these studies, we will have identified the number of cells or crypts necessary to be assayed to characterize the neoplasia. Based on these results, we will propose a follow-up grant for the systematic validation of chemical cytometry for prognosis of the progression to adenocarcinoma, and for the development of a platform appropriate for large-scale clinical analysis.